sudo xcode-select --reset swift build

SwiftBuildWhenSomethingIsWrong.sh

sudo xcode-select --reset
swift build


// The whole process

swift package init --type executable 
swift build 
swift run <app-name>

// Adding dependencies (RxSwift example)

import PackageDescription

let package = Package(
  name: "RxTestProject",
  dependencies: [
    .package(url: "https://github.com/ReactiveX/RxSwift.git", "4.0.0" ..< "5.0.0")
  ],
  targets: [
    .target(name: "RxTestProject", dependencies: ["RxSwift", "RxCocoa"])
  ]
)

// And then

swift build
swift package update
swift package generate-xcodeproj

// To make release build

swift package update
swift build -c release // -c is for --configuration
swift run -c release